POS0162 VALIDITY OF SIMPLIFIED ULTRASONOGRAPHIC ASSESSMENTS OF JOINT INFLAMMATION IN RHEUMATOID ARTHRITIS
Authors: Z. Rutter-Locher, K. Chaabo, E. Chan, A. Vincent, S. Norton, L. B. Kirkham
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Musculoskeletal ultrasound (MSK US) is a valuable tool to aid management of inflammatory arthritis. It's use in clinical practice is limited by the feasibility and time constraints of performing a full 44 or 78 joint ultrasound. <h3>Objectives</h3> Our objective was to determine the validity of four previously published simplified approaches (6 joint<sup>[1]</sup>, 12 joint<sup>[2]</sup>, hands only<sup>[3]</sup> and data driven<sup>[4]</sup> US models) in a new patient cohort, in order to guide future choice of targeted MSK US protocol in research and clinical practice. <h3>Methods</h3> Sequential patients with rheumatoid arthritis, diagnosed according the 1987 ACR criteria, with a DAS28ESR score ≥ 3.2 underwent clinical assessment and 44 joint US at Guy's Hospital. Grey scale (GS) and power doppler (PD) were graded semi quantitatively, according to the EULAR-OMERACT criteria. All the joints scored in the simplified 6 joint, 12 joint, hands only and "data driven" models were included in the current 44 joint US. However, the number of synovial recesses examined differed from those in the simplified models. Sensitivity of the simplified models to detect GS and PD signal, compared to the extended 44 joint US was calculated. Content validity was evaluated by correlating the 44-joint US count with the simplified models using Spearman's correlation coefficient. The proportion of information retained by the simplified models compared with the 44 joint US was assessed using linear regression analysis. <h3>Results</h3> 158 patients were enrolled in the study, with a mean age of 58.9 years (SD 12.95), 78.5% Female, 67.7% RhF positive and a median disease duration of 10 years (IQR 5-19.2). Median DAS 28 was 4.8 (IQR 3.9-5.6) and pain VAS 55 (IQR 40-70). GS and PD positivity was most common at the wrist and the MTP joints (Figure 1). All simplified assessment models were sensitive and able to detect &gt;85% of patients with GS≥ 2 PD≥1 evaluated using the 44 joint (6 joint GS≥ 2 135 (88.2%), PD≥1 75 (86.2%), 12 joint GS≥ 2 137 (89.5%), PD≥1 76 (87.4%), Hands only GS≥ 2 138 (90.2%), PD≥1 80 (92%), Data Driven GS≥ 2 149 (97.2%), PD≥1 82 (94.3%). GS, PD and total scores for all the simplified models significantly correlated with the scores from the 44 joint US (Table 1). The "data driven" model had the highest correlation and retained the greatest proportion of information compared with the total 44 joint US scores. <h3>Conclusion</h3> This study validates the use of the 6 joint, 12 joint, hands only and data driven approaches in a new patient cohort. The data driven approach was the most sensitive and retained the greatest proportion of information. Simplified US models enable the routine use of musculoskeletal US in clinical practice. <h3>References</h3> [1]Aydin, S. Z. <i>et al.</i> Six-joint ultrasound in rheumatoid arthritis: a feasible approach for implementing ultrasound in remission. <i>Clin Exp Rheumatol</i><b>35</b>, 853–856. [2]Naredo, E. <i>et al.</i> Validity, reproducibility, and responsiveness of a twelve-joint simplified power Doppler ultrasonographic assessment of joint inflammation in rheumatoid arthritis. <i>Arthritis Care Res (Hoboken</i>) <b>59</b>, 515–522 (2008). [3]Hammer, H. B., Kvien, T. K. &amp; Terslev, L. Ultrasound of the hand is sufficient to detect subclinical inflammation in rheumatoid arthritis remission: a post hoc longitudinal study. <i>Arthritis Res Ther</i><b>19</b>, 221 (2017). [4]Aga, A.-B. <i>et al.</i> First step in the development of an ultrasound joint inflammation score for rheumatoid arthritis using a data-driven approach. <i>Ann Rheum Dis</i><b>75</b>, 1444–1451 (2016). <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> Zoe Rutter-Locher: None declared, Khaldoun Chaabo: None declared, Estee Chan: None declared, Alexandra Vincent: None declared, Sam Norton: None declared, L Bruce Kirkham Speakers bureau: Abbvie, Eli Lilly, Galapagos, Janssen, Novartis, Pfizer, UCB , Grant/research support from: Eli Lilly.